A short, or something else?

Also, just twist the light switch knob vigorously from left to right several times. These get dirty, and this might scrape the corrosion off

Thank you 67Dart273 - this worked!

The blinker issue: I traced all the wires looking for damage and they were actually ok. Took the glove box out/off and found the flasher relay near the ashtray - twisted up and half plugged in. Pretty sure the flasher had been replaced (the "made in mexico" stamped on it gave it away).

Cleaned off the pins, mated and de-mated a couple of times and voila! All lights back to normal operating status.

I think my next project will be converting the amp bypass mod, as explained here: http://www.madelectrical.com/electricaltech/amp-gauges.shtml